Richards_2012_Arch.Insect.Biochem.Physiol_79_61

The current work demonstrates that larvae of the ectoparasitic wasp, Eulophus pennicornis, produce salivary secretions (Ep S) that contain a variety of hydrolases. This includes medium to high levels of N-acetyl-beta-glucosaminidase activity, relatively low levels of esterase (C 4) and lipase (C 14) activity, and trace levels of esterase lipase (C 8), acid phosphatise, beta-galactosidase, beta-glucuronidase, and alpha-glucosidase activity. In addition, in vitro monolayer assays indicate that both a 4 h and an 18 h incubation of hemocytes from host Lacanobia oleracea larvae in Ep S significantly increases (P < 0.001) the percentage of cells dying by apoptosis compared to the controls. Moreover, an 18 h incubation of hemocytes in Ep S (but not a 4 h incubation), also significantly increased the percentage of dead cells detected using a trypan-blue exclusion assay. The role of ectoparasitoid salivary secretions in conditioning the host by disabling hemocyte-mediated wound healing responses, and providing food for the developing wasp larvae is discussed.